Trocar having protector with sinusoidal member

ABSTRACT

A surgical trocar has a cannula assembly including a sleeve having a proximal end, a distal end and a passageway therethrough. A housing having an opening is located at the proximal end of the sleeve and is aligned with the passageway of the sleeve. The trocar also includes an obturator assembly which is insertable in the cannula assembly. The obturator assembly includes a handle and an obturator shaft. The obturator shaft has a proximal end connected to the handle and a distal end opposite the proximal end. A penetrating tip is located at the shaft distal end for penetrating tissue. A protector having a distal end is slidably disposed around the obturator shaft for covering the penetrating tip. The protector has an aperture at its distal end for permitting the penetrating tip to pass therethrough. The protector also includes a flexible proximal end movable against the obturator handle to expose the penetrating tip when a proximal force is asserted against the protector. The flexible proximal end of the protector includes a sinusoidal member for contacting the obturator handle.

This application is a continuation application of U.S. patentapplication No. 09/057,687 filed Apr. 9, 1998 which is a divisionalapplication of U.S. patent application No. 08/827,317 filed Mar. 26,1997, now U.S. Pat. No. 5,879,382.

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates in general to endoscopic surgery, and inparticular, to trocars having shields or protectors for use inendoscopic surgical procedures.

The use of endoscopic procedures in surgery has become widely accepted.The term endoscopic as used herein is defined to include all types ofminimally invasive surgical procedures including laparoscopic andarthroscopic procedures. Accordingly, numerous endoscopic instrumentshave been developed which allow the surgeon to perform complex surgicalprocedures with minimal incisions into the skin and tissue surrounding aparticular body cavity or anatomical region. In order to introduce theendoscopic instrumentation into the body cavity, it is often necessaryto puncture and cannulate the body cavity by using a trocar. Trocars arewidely known in the art and typically consist of an obturator and atrocar cannula. It is common for a sealing arrangement or seal assemblyto be used in association with the cannula to prevent the escape offluid or gas during endoscopic procedures. Trocars may have a protectiveelement around the obturator which covers the sharp piercing tip of theobturator prior to and after insertion, and also after removal of theobturator and trocar cannula. The protective element is often referredto as a safety shield or protector.

One type of trocar utilizes a safety shield and is typically inserted bypressing the distal end of the trocar assembly against the outer skin ofthe patient with sufficient force to cause the piercing end of theobturator to pierce through the skin, underlying fat, muscle and fasciainto the body cavity. The trocar is permitted to penetrate into the bodycavity because the safety shield is retracted proximally therebyexposing the sharp piercing tip. However, upon completing thepenetration, the safety shield automatically returns to its protectiveposition covering the piercing tip. This type of trocar is a fullyreturnable safety shielded trocar. Once the surgeon has properlypositioned the trocar within the body cavity, the obturator togetherwith the safety shield are removed and the trocar cannula is thenavailable as a pathway, e.g., for insertion of endoscopicinstrumentation. U.S. Pat. No. 5,387,197 (Smith et al.) describes thistype of trocar.

With current fully returnable safety shielded trocars, it may benecessary to remove the cannula handle from the obturator handle to"reload" the shield on the trocar obturator for those instances wherethe trocar has not completely penetrated into the body cavity. In thisfashion, therefore, it is necessary to perform an extra step while theobturator tip is inserted within pneuoperitoneum.

Yet, in some procedures it may be desirable to utilize trocars without asafety shield or to utilize a trocar design wherein the trocar obturatoris nonshielded at the time when the trocar obturator is placed withinthe trocar cannula. Thus, upon coupling of the shielded obturator andthe cannula, the shield will be retracted thereby exposing the piercingtip of the obturator. This type of trocar can be referred to as anassembly actuated trocar.

An assembly actuated trocar prevents the shield from returning to itsprotective position upon placement of the obturator within the cannula.U.S. Pat. No. 5,248,298 (Bedi et al.) describes this type of trocar. Inthis way, the user is able to slightly withdraw the trocar from thepierced tissue, and then continue penetrating through remaining tissuelayers. This prevents what is commonly referred to as "tenting" ofpneumoperitoneum. In this fashion, tenting can be reduced while stilladequately providing access to the body cavity.

In an effort to eliminate problems with tenting or to reduce cost fromsurgery, surgeons often utilize trocars that do not employ a safetyshield since these types of trocars are generally less expensive thanfully returnable safety shielded trocars. However, for those proceduresthat utilize trocars without a safety shield, there is a possibilitythat the obturator tip could cut a person handling the trocar or damagethe trocar seal assembly or other components of the instrument.

Presently, there is no known trocar that provides a low cost option tothe surgeon while maintaining the ability to protect the obturatorpiercing tip with a shield or protector up until the time when theobturator is coupled to the proximal end of the cannula.

SUMMARY OF THE INVENTION

The present invention is a surgical trocar for use in endoscopicsurgical procedures such as minimally invasive procedures, laparoscopicprocedures, arthroscopic procedures or the like.

The surgical trocar according to the present invention comprises acannula assembly including a sleeve having a proximal end, a distal endand a passageway therethrough. A housing having an opening is located atthe proximal end of the sleeve and is aligned with the passageway of thesleeve. The trocar also includes an obturator assembly which isengagable with the cannula assembly. The obturator assembly includes ahandle and an obturator shaft. The obturator shaft has a proximal endconnected to the handle and a distal end opposite the proximal end. Apenetrating tip is located at the distal end of the obturator shaft.

The obturator assembly also includes a protector slidably disposedaround the obturator shaft for covering the obturator penetrating tip.The protector has an aperture at a distal end of the protector forpermitting the penetrating tip of the obturator shaft to passtherethrough. The protector also includes a flexible proximal end whichis slidably movable against a contact portion of the handle for exposingthe penetrating tip past the protector aperture and the sleeve distalend when the handle comes in contact with the housing upon the insertionof the obturator assembly into the cannula assembly. Thus, uponinserting the obturator assembly into the cannula assembly, a proximalforce is applied to the protector which moves the protector proximallysuch that the flexible proximal end of the protector slidably movesagainst the contact portion of the handle. This contact causes theflexible proximal end to flex or deflect as the flexible proximal end isslidably moved against the contact portion of the handle.

According to the present invention, there are several embodiments forthe flexible proximal end of the protector. One embodiment includes apair of deflectable arms. A second embodiment for the flexible proximalend of the protector includes a sinusoidal member integral with theprotector.

Another alternative embodiment according to the present inventionprovides a surgical trocar, and more particularly, an obturator assemblycomprising a handle having an opening therein and a flexible engagementportion. The obturator shaft extends through the handle opening and hasa proximal end fixed to the handle and a distal end with a penetratingtip thereon. A protector is slidably disposed around the obturator shaftand extends through the handle opening for covering the penetrating tipof the obturator shaft. The protector has an aperture at a distal endthereof which permits the penetrating tip of the obturator shaft to passtherethrough. The protector also has a proximal end which is slidablymovable against the flexible engagement portion of the handle in orderto retract the protector to a retracted position for exposing thepenetrating tip when a proximal force is placed against the protector.

One advantage of the present invention is to provide a surgical trocarthat provides protection for the surgeon or others all the way up untilthe moment that the obturator assembly is engaged with the cannulaassembly.

Another advantage according to the present invention is to provide asurgical trocar that provides protection for the trocar seal and othercomponents of the trocar.

Another advantage of the present invention is to provide a surgicaltrocar that eliminates tenting of the peritoneum.

It is another advantage of the present invention to provide a surgicaltrocar having an obturator protector to be used as a secondary port forendoscopic surgical procedures.

The various features of novelty which characterize the invention arepointed out with particularity in the claims annexed to and forming apart of this disclosure. For a better understanding of the invention,its operating advantages and specific objects attained by its uses,reference is made to the accompanying drawings and descriptive matter inwhich preferred embodiments of the invention are illustrated.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a trocar having an obturator and acannula according to the present invention;

FIG. 2 is a plan view in section of the trocar obturator with apenetrating tip in a covered position according to the presentinvention;

FIG. 3 is a plan view in section of the obturator of FIG. 2 in a coupledrelationship with the cannula of FIG. I with the penetrating tip in anexposed position;

FIG. 4 is a perspective view, partially broken away, illustrating aprotector according to the present invention;

FIG. 5 is an exploded perspective view of the obturator and the cannulaof FIG. 1;

FIG. 6 is a perspective view of a seal assembly employed in the cannulaof FIG. 5;

FIG. 7 is a side elevational view of the seal assembly shown in FIG. 6;

FIG. 8 is a front elevational view of the seal assembly shown in FIG. 6;

FIG. 9 is a plan view in section of an alternative embodiment of atrocar according to the present invention; and

FIG. 10 is an alternate embodiment of the protector of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As best shown in FIG. 1 the present invention is a low cost surgicaltrocar, generally designated 20, utilized as an assembly actuated trocarfor endoscopic surgical procedures to include all minimally invasivesurgical procedures such as laparoscopic and arthroscopic surgicalprocedures. The surgical trocar 20 is disposable and is intended to beused as a single patient use only device, meaning that the trocar 20according to the present invention is to be used on only one patient fora particular surgical procedure and then after such usage, the trocar 20is to be discarded.

The surgical trocar 20 is similar to the trocars found in U.S. patentapplication Ser. Nos. 08/543,455 (Oct. 16, 1995); 08/543,547 (Oct. 16,1995); 08/572,172 (Dec. 13, 1995); 08/694,980 (Aug. 9, 1996) and U.S.Pat. Nos. 4,535,773; 5,224,952; 5,256,149; 5,314,417; 5,387,197;5,248,298; 5,330,437; 5,399,167; 5,066,288; 5,215,526 and 5,267,965 allof which are incorporated herein by reference.

The surgical trocar 20 includes an obturator assembly, generallydesignated 30, which is insertable through a cannula assembly, generallydesignated 80, for establishing a surgical access port. FIG. 2 shows theobturator assembly 30 comprising a handle 32 having an opening 34 at alower portion of the handle 32. The handle 32 also includes a contactportion, generally designated 36, having a pair of first retaining ribs37 and a pair of second retaining ribs 39 positioned proximally to thepair of first retaining ribs 37. Additionally, the contact portion 36also includes a first ramp surface 41 and a second ramp surface 43positioned at an obtuse angle to the first ramp surface 41.

An obturator shaft 45 having a first retained portion 47 and a secondretained portion 49 at a proximal end of the obturator shaft 45 arefixedly secured to the handle 32 at the first retaining ribs 37 and thesecond retaining ribs 39 respectively. The remainder of the obturatorshaft 45 extends from the handle 32 through the handle opening 34.

The obturator shaft 45 also includes a penetrating tip, generallydesignated 50, which is a blade assembly comprising a flat blade 55 forpenetrating tissue and a pair of upper shoulders 53. The penetrating tip50 is fixed to the distal end of the obturator shaft 45.

A protector sleeve 57 having a channel 61 therethrough is slidablydisposed around the obturator shaft 45. The protector 57 also includes aflexible proximal end 59 which is located, along with the proximalportion of the obturator shaft 45, within the handle 32. As shown inFIG. 4, the protector 57 is a single piece of molded plastic. Theprotector proximal end 59 includes a pair of deflectable arms 62 thatare resilient and flexible enough so that the deflectable arms 62 can bedeflected outwardly from the obturator shaft 45, but yet resume theiroriginal shape and size after deflection without breaking away from theprotector 57. However, it is not intended that the protector 57 belimited merely to molded plastic, but can also include any type ofmaterial that contains the required properties and characteristics forthe flexible proximal end 59 such as described above.

The protector deflectable arms 62 include an inner surface 64 and an endsurface 68 at the end portion of each deflectable arm 62 as shown inFIG. 4. The end surfaces 68 of the protector deflectable arms 62 areinitially located distally from the first ramp surfaces 41 of the handlecontact portion 36 thus defining a gap between the first ramp surfaces41 and the deflectable arm end surfaces 68.

Similar to the obturator shaft 45, the protector 57 extends from thehandle 32 through the handle opening 34. The protector 57 also includesa dilating tip section 67 located at the distal end of the protector 57for dilating tissue after the trocar 20 is inserted into tissue forestablishing a surgical access port.

The protector 57 also includes a boss 66 circumferentially arrangedaround the exterior of the protector 57 and positioned near the handleopening 34. The dilating tip section 67 of the protector 57 includes anaperture 60 which communicates with the channel 61 of the protector 57.The aperture 60 is located at the distal end of the protector 57 forpermitting the penetrating tip 50 of the obturator shaft 45 to passtherethrough.

The dilator tip 67 also includes a slot 69 which vertically extends fromthe aperture 60 to a point near the distal end of the protector 57 forpermitting the penetrating tip 50 to pass therethrough (FIG. 4). Theprotector 57 also includes a stop 65 circumferentially arranged withinthe channel 61 at the dilator tip 67 for being supported by with theupper shoulders 53 of the penetrating tip 50.

Since, the flexible proximal end 62 of the protector 57 is located nearthe contact portion 36 within the handle 32, the protector 57 isslideably movable around the obturator shaft 45 between the uppershoulders 53 of the penetrating tip 50 of the obturator shaft 45 and thehandle contact portion 36. The stop 65 is supported by the uppershoulders 53 of the penetrating tip 50 for preventing the protector 57from disengaging from the obturator handle 32.

As best illustrated in FIG. 2, the obturator assembly 30 is in aprotected position meaning that the protector 57 is extended beyond thepenetrating tip 50 thereby covering the penetrating tip 50 andpreventing any inadvertent cutting by the flat blade 55.

FIG. 5 shows the cannula assembly 80 comprising a cannula sleeve 82defining a central passageway therethrough and a seal housing 85 locatedat the proximal end of the sleeve 82. The sleeve 82 has a helical thread83 on an exterior surface of the sleeve 82 for positioning the sleeve 82in tissue. The housing 85 also includes a handle portion 84 whichextends outwardly and substantially perpendicular from opposite sides ofthe housing 85. The housing 85 includes a central opening 87 forreceiving a seal assembly, generally designated 100, therein. The sealassembly 100 is disposed in the central opening 87 and is seated abovethe cannula sleeve 82. The housing 85 also includes a seal retainer 90having two retainer locks 92 and is seated against the upper surface ofthe seal assembly 100 and fixed to the cannula housing 85. The sealretainer 90 is a conical plastic ring which permits the obturatorassembly 30 to be inserted directly through the seal assembly 100.

The housing 85 also includes a pair of retainer lock slots 86 located onopposite sides of the housing 85 for receiving the retainer locks 92 ofthe seal retainer 90. Accordingly, the retainer locks 92 of the retainer90 are pressed fit into the retainer lock slots 86 of the housing 85 asbest illustrated in FIG. 1.

As best illustrated in FIG. 3, the penetrating tip 50 is exposed byretracting the protector 57 to a retracted position proximally withinthe cannula handle 32. Upon a proximal force F being asserted againstthe protector 57, the deflectable arm end surfaces 68 contact the firstramp surfaces 41 of the handle contact portion 36 and are slidablymovable across the first ramp surfaces 41 of the handle contact portion36. After initial contact of the end surfaces 68 with the first rampsurfaces 41, the deflectable arms 62 are deflected outwardly away fromthe obturator shaft 45 as the protector 57 is forced proximally withinthe handle 32 through the application of proximal force F since thedeflectable arms 62 are made of a resilient, flexible material. Due thematerial properties of the proximal end 59, an opposing force is appliedto the protector 57 as the deflectable arms 62 are slidably movedagainst the contact portion 36. These material properties cause theprotector 57 to return distally to a protected position when theproximal force F is released from the protector 57.

Once the deflectable arm end surfaces 68 are slid past the first rampsurfaces 41, the inner surfaces 64 of the deflectable arms 62 contactthe second ramp surfaces 43 of the handle contact portion 36 and areslidably movable across the second ramp surfaces 43. Accordingly, theend surfaces 68 and the inner surfaces 64 of the deflectable arm 62 areslideably movable against the first ramp surfaces 41 and the second rampsurfaces 43 of the handle contact portion 36 respectively to facilitatea smooth retraction of the protector 57 within the obturator handle 32.The first ramp surfaces 41 are arranged substantially perpendicular tothe obturator shaft 45 in order to provide a sufficient resistivesurface for the deflectable arms 62 to prevent the deflectable arms 62from easily sliding past the first ramp surfaces 41. This arrangementensures that the protector 57 is not inadvertently withdrawn into theobturator handle 32 until intended. Because the second ramp surfaces 43are at an obtuse angle with respect to the first ramp surfaces 41, thereis a less resistive surface for the deflectable arms 62. This allows theprotector 57 to be easily retracted at this point in the retraction.

The protector is retracted to its retracted position through theapplication of the proximal force F which can be applied to theprotector 57 manually, for instance, by the surgeon grasping theprotector boss 66 and withdrawing the protector 57 proximally toward thehandle 32. Alternatively, the protector 57 is retracted to its retractedposition upon insertion of the obturator assembly 30 through the cannulaassembly 80 and into the cannula sleeve 82 until the dilator tip 67 ofthe protector 57 extends through the distal end of the cannula sleeve 82as shown in FIGS. 1 and 3 and up until the point where the protectorboss 66 contacts the handle 32 at the handle opening 34. At this point,the boss 66 of the protector 57 will contact the inner surface of theconically-shaped retainer 90 thereby causing the proximal force F to beasserted against the protector 57. The proximal force F advances theprotector 57 proximally within the handle 32 for extending thepenetrating tip 50 through the protector aperture 60 thereby exposingthe flat blade 55 for cutting tissue. The handle opening 34 has asmaller diameter than the outer diameter of the circumferentiallyarranged protector boss 66 such that the protector boss 66 cannot beinserted within the obturator handle 32.

Additionally, as shown in FIG. 5, the obturator handle 32 also includesretaining pins 33 laterally extending from the handle adjacent thehandle opening 34. Thus, the obturator assembly 30 can be locked to thecannula assembly 80 by rotating the retaining pins 33 into the pin slots94 of the seal retainer 90 through a slight rotation motion of thehandle 32 once the obturator assembly 30 has been inserted through thecannula assembly 80 thereby forming the assembly actuated trocar 20.

The handle 32 is unlocked merely through reversing the rotation actionsuch that the rotating pins 33 disengage from the pin slots 94 whichwill cause the protector 57 to return to its protected position coveringthe penetrating tip 50. The resilient, flexible properties of theprotector proximal end 59 will cause the protector 57 to advancedistally over the penetrating tip 50 upon the decoupling of the handle32 from the cannula housing 85.

As shown in FIGS. 6-8, the seal assembly 100 includes a housing seal 104which is a circumferential elastomeric member that surrounds a diaphragmseal 108. The diaphragm seal has a central aperture 110 therethrough andhas a substantially convex shape which extends upwardly and outwardlyfrom the housing seal 104. A flange 112 surrounds the outer periphery ofthe housing seal 104.

Additionally, the seal assembly 100 includes an S-shaped pressure seal120 comprising two sidewalls 122 extending distally from the under sideof the housing seal 104 and the diaphragm seal 108. As shown in FIG. 8,each sidewall 122 has an end section 126 that is adjacent to each otherand define an S-shaped slit 128 therebetween. Accordingly, the centralaperture 110 and the S-shaped slit 128 of the seal assembly 100 permitthe obturator assembly 30 to be inserted therethrough in sealingengagement thereby preventing the loss of operating fluid. However, oncethe cannula assembly 80 has been placed, the obturator assembly 30 canbe withdrawn from the cannula assembly 80 for the insertion ofadditional surgical instruments through the cannula assembly 80 forfacilitating the surgical procedure. Similar to obturator assembly 30,additional surgical instruments inserted through the seal assembly 100are sealed by the seal assembly 100, particularly by the S-shapedpressure seal and the diaphragm seal 108.

A second embodiment of a protector 57a according to the presentinvention is illustrated in FIG. 10 wherein the protector 57a includes aflexible proximal end 59a which is a sinusoidal member 72 having acentral bore 73 and a pair of proximal tips 74 having a notch 76interposed between each tip 74. The notch 76 and the central bore 73 arealigned directly with the channel 61 of the protector 57a. Both thenotch 76, the central bore 73, along with the channel 61 of theprotector 57a are shaped to receive the obturator shaft 45 due to theirdirect alignment with each other. The proximal tips 74 are positionednear the first ramp surfaces 41 of the handle engagement portion 36 forcontacting the first ramp surfaces 41 upon proximal force F beingasserted against the protector 57a in the manner described above. Thetips 74 are relatively flat members that will contact the first rampsurfaces 41 without advancing to the second ramp surfaces 43.

Similar to the protector 57 (FIG. 4) described above, the protector 57ais also made of molded plastic as single, integral component. Thesinusoidal member 72 through both its configuration and materialcomposition is a resilient, flexible member which permits the protector57a to function similar to the protector 57 (FIG. 4) described above.

Another embodiment according to the present invention is illustrated inFIG. 9 wherein the trocar 20 includes a protector 57b having a proximalend 70. The contact portion 36 of the cannula handle 32 comprises a pairof deflectable members 48 that are movable by the proximal end 70 of theprotector 57b. The deflectable members 48 are made of a flexible andresilient material such that once the proximal force F is assertedagainst the protector 57b, the proximal end 70 of the protector 57b isadvanced proximally into the contact portion 36 slidably moving againstthe inner surfaces of the deflectable members 48. The protector proximalend 70 outwardly deflects the deflectable members 48 away from theobturator shaft 45 thereby retracting the protector 57b and exposing thepenetrating tip 50. Accordingly, this alternative arrangement providessimilar advantages to the preferred embodiment shown in FIGS. 2-5.

As mentioned above, the trocar 20 according to the present inventionprovides several advantages. In particular, the trocar 20 is an assemblyactuated trocar and is directed to being the trocar of choice in thecurrent cost conscious surgical environment. Since cost is a major issuewith the present surgical community, it is often necessary to developnovel and creative instruments and techniques in order to provide safe,efficacious and quality surgical treatment for the patient, while at thesame time seeking to reduce cost from the surgical procedure. Onecreative way of reducing cost from a surgical procedure afforded by thepresent invention, is to utilize a single fully returnable safetyshielded trocar such as those described as part of the field andbackground of the invention, along with one or more of the trocars 20according to the present invention.

Since a fully returnable shield trocar is more costly than the trocar 20according to the present invention, mainly due to the cost of additionalparts and manufacturing, many surgeons will seek to limit the number offully returnable safety shielded trocars utilized during a singlesurgical procedure. Thus, many surgeons may opt to utilize only onefully returnable safety shielded trocar in order to establish a primaryaccess port in the patient. The primary access port being establishedonce the safety shielded obturator is removed from the cannula and anendoscope is inserted in its place in order to establish visualizationfor the placement for secondary access ports.

The secondary access ports are utilized to accommodate various types ofsurgical instrumentation in order to facilitate the surgical procedure.Accordingly, the trocar 20 according to the present invention can beutilized to establish these secondary access ports. As illustrated inFIG. 2, since the trocar 20 according to the present invention utilizesa protector 57, the penetrating tip 55 will be covered, and accordingly,a degree of safety is provided to all those who handle the obturatorassembly 30 prior to the engagement and locking of the obturatorassembly 30 into the cannula assembly 80. Additionally, the sealassembly 100 of the trocar 20 also will be protected since thepenetrating tip 55 remains covered as the obturator is slid through theseal assembly 100 into the cannula sleeve 82.

Although this invention has been described in connection with its mostpreferred embodiments, it will become readily apparent to thosereviewing this detailed specification that numerous additionalembodiments fall well within the scope and spirit of the claimedinvention as set forth in the claims which appear below.

What is claimed is:
 1. An improved surgical trocar comprising a cannula assembly including a sleeve having a proximal end and a distal end and a passageway therethrough and a housing having an opening and being located at said proximal end of said sleeve, said housing opening being aligned with said passageway of said sleeve, an obturator assembly insertable into said cannula assembly and including a handle, an obturator shaft having a proximal end connected to said handle and a distal end opposite said proximal end, and a penetrating tip located at said distal end of said obturator shaft, wherein the improvement comprises:a protector having a distal end and slidably disposed around said obturator shaft for covering said penetrating tip of said obturator shaft, said protector having an aperture at said distal end for permitting said penetrating tip of said obturator shaft to pass therethrough; said protector also having a flexible proximal end movable against said handle to a retracted position in order to expose said penetrating tip past said protector aperature and said sleeve distal end when a proximal force is exerted against said protector, said flexible proximal end including a sinusoidal member for contacting said handle.
 2. The surgical trocar according to claim 1, wherein said sinusoidal member includes a pair of tips and a notch interposed therebetween at a proximal end of said sinusoidal member.
 3. The surgical trocar according to claim 2, wherein said sinusoidal member also includes a central opening therethrough, said central opening and said notch shaped to receive said obturator shaft.
 4. The surgical trocar according to claim 3, wherein said protector includes a boss for contacting said handle when said protector is retracted to said retracted position.
 5. The surgical trocar according to claim 4, including a seal assembly located in said opening of said housing.
 6. The surgical trocar according to claim 5, wherein said housing includes at least one slot and said handle includes at least one pin detachably engagable with said at least one slot for locking said handle to said housing.
 7. The surgical trocar according to claim 6, wherein said penetrating tip includes a flat blade.
 8. The surgical trocar according to claim 7, wherein said protector includes a dilation section at said distal end of said protector.
 9. The surgical trocar according to claim 8, wherein said sleeve includes a helical thread on an exterior surface of said sleeve. 